1. Field of the Invention
The present invention relates to a novel process for producing 1.alpha.3.beta., 24-trihydroxy-.DELTA..sup.5 -steroid compounds from 1.alpha., 2.alpha.-epoxy-.DELTA..sup.4,6 -3,24-dioxo steroid compounds. The 1.alpha., 3.beta., 24-trihydroxy-.DELTA..sup.5 -steroid compounds are useful for producing 1.alpha., 24-dihydroxy-vitamin D.sub.3 derivatives according to, for example, a process described in Japanese Unexamined Patent Publication No. 56-92266. Accordingly, the present process is a unit process in the synthesis of vitamin D.sub.3 derivatives.
2. Description of the Related Art
As processes for the production of 1.alpha., 3.beta., -dihydroxy-.DELTA..sup.5 -steroid compounds, Japanese Examined Patent Publication Nos. 53-9222, 53-24073, and 58-54160 disclose processes wherein 1.alpha., 2.alpha.-epoxy-.DELTA..sup.4,6 -3-oxosteroid compounds are reduced by an alkaline metal and a proton donor in a mixed solvent comprising liquid ammonia. But, the application of the conventional processes to the production of 1.alpha., 3.beta., 24-trihydroxy-.DELTA..sup.5 -steroids provides a yield lower than that when applied to the production of 1.alpha., 3.beta.-dihydroxy-.DELTA..sup.5 -steroids and therefore, the processes are disadvantageous from an industrial point of view.